The field of endoscopic surgery has been advancing rapidly in recent years. In this form of surgery, procedures are performed inside the body of a patient using instruments inserted through small incisions or ports in the body. The surgery is performed with the aid of an endoscope, which is a thin, tube-like instrument featuring a light source, viewing lenses, and/or various other attachments such as irrigators, scissors, snares, brushes or forceps. Endoscopes may be flexible or rigid, and normally utilize optic fibers to transmit light to the internal cavity. The surgery is normally viewed by the surgeon through an ocular. Lenses are placed near the distal tip of the endoscope and the image thereon is transmitted via optic fibers or other lens systems to the ocular or viewer. Other types of endoscopes utilize optic fibers to transmit electronic signals representing the internal image from the distal lens to a video monitor which is viewed by the surgeon.
This form of surgery allows internal visualization of the body structure without the necessity of excessive dissection of tissue. Typical endoscopes are in the 5 to 12 mm diameter range and thus require only very small incisions for insertion into the body.
Endoscopic surgery has developed rapidly because of the numerous benefits arising in favor of the patient. Since there is only a small incision to permit the entrance of the endoscope and other endosurgical devices, endoscopic surgery results in less trauma to the patient's body and faster patient recovery. For the benefits of endoscopic surgery to arise, however, all aspects of the surgery, such as the initial examination, retraction of internal organs, and the surgical procedure itself, must be capable of being performed through small endoscopic incisions or ports.
The obvious difficulty associated with endoscopic surgery is inadequate visualization of the internal structure required to properly complete the surgical procedure. Endoscopic surgery is thus difficult in areas which are typically difficult to reach, such as the gallbladder. In the surgical removal of the gallbladder, also known as cholecystectomy, the tissue and organs surrounding the gallbladder are examined using an endoscope and retracted in order to properly expose the organ which is to be removed.
Currently, endoscopic procedures in the abdominal cavity, otherwise known as laparoscopy, often require retraction. Specifically, endoscopic procedures involving the gallbladder entail retracting the liver, which rests directly above the gallbladder. In an open surgery procedure, retraction such as this is relatively easy, as the surgery involves the exposure of the entire abdominal cavity. In order to obtain the benefits of endoscopic surgery, however, a form of retraction which can be accomplished through endoscopic ports is necessary.
In an endoscopic procedure involving the gallbladder or other abdominal organ, retraction is currently accomplished by inflating the peritoneal cavity with carbon dioxide. This method of retraction requires a small endoscopic port for the introduction of the gas source. The gas is introduced into the body through a trocar, and a state of pneumoperitoneum occurs. The gas inflates the peritoneal cavity so as to cause the skin and muscles to separate from and rise above various organs and tissue, creating the exposure necessary to accomplish the endoscopic surgery.
Several problems are associated with pneumoperitoneal retraction however. First of all, exposure of the organs remains adequate only while the required pneumoperitoneal state remains. Since endoscopic surgery normally requires the introduction of at least the endoscope, and more often several other endoscopic instruments, several endoscopic ports will most likely be created in the patient's body. Each of these ports, which normally use a cannula to keep them open for access, in effect create an exhaust port for the gas. The risk that insufflation pressure may be lost increases the risk that the endoscopic procedure may go awry as adequate exposure for the endoscope is eliminated.
Further, there are many complications which are associated with persistent pneumoperitoneum during an endoscopic procedure. Acute cardiovascular collapse secondary to over-distension of the abdomen, vasovagal reflex activation, cardiac arrhythmia, pneumothorax, subcutaneous emphysema, alteration of large vein venous return, retinal hemorrhage, blindness, carbon dioxide embolism, and general patient discomfort have all been associated with persistent pneumoperitoneum.
In addition, pneumoperitoneal retraction is effective in retracting only the muscles and tissue from above the organs. The organs themselves are not, to a great extent, retracted from each other.
Lastly, current mechanical retractors are often made of stainless steel or other metals. Use of metal retractors in the presence of other endoscopic surgical tools may result in inadvertent electrical or laser injury. Additionally, such retractors can cause inadvertent tearing, slicing, puncture or other mechanical injury to the internal tissues and organs.
There is therefore a need for a device and method which provide retraction in conjunction with endoscopic procedures which is effective in providing adequate visualization and which is safe and has fewer side effects than current retraction methods.